1. Field of the Invention
The present invention relates to a light guide module and an optical detection device thereof, and more particularly, to a light guide module with low signal interference and high detecting accuracy and an optical detection device thereof.
2. Description of the Prior Art
A light guide plate is a key element of the backlight module for guiding directions of light transmission. The light guide plate applied to the edge-type backlight module can increase illumination of the panel and uniformly control the illumination. The lighting unit of the conventional edge-type backlight module is disposed by a side of the light guide plate. A beam emitted from the lighting unit can enter the light guide plate through its side surface, and is transmitted to a far end of the light guide plate by total internal reflection. A plurality of reflection parts is printed on the bottom of the light guide plate. The total internal reflection inside the light guide plate can be interfered by the reflection parts, and the reflection parts can further transmit the beam out of the light guide plate upwardly by reflection. The illumination of the panel corresponds to dimensions and arrangements of the reflection parts. The conventional edge-type light guide plate is merely utilized in the backlight module without the other application. Thus, design of an optical detection device that utilizes the edge-type light guide plate to be an optical sensor for high sensitivity and preferred accuracy is an important issue in the optical industry.